Comminuting mill



April 23, 1929. R; c, NEWHQUSE 13 710,666

COMMINUTING MILL Filed March 1928 mom/W hatented Apr. 23, 1929.

UNITED STATES 1,710,666 PATENT OFFICE.

nan c. NEWHOUSE, or MILWAUKEE, WISCONSIN, ASSIGNOR r ALLIS-GHALMEBSracrunme COMPANY, or MILWAUKEE, WISCONSIN, a conroaarron or EELAWABE.

oomamurmo 11111..

Application filed larch 8, 1928. Serial in. 259,968.

This invention relates generally to improvements in the construction andoperat on of rotary comminuting mills for reducing granular material toa fine powder.

An object of the invention is to provide a new and useful comminutingmill for ellectively reducing granular material such as cement clinker,to a line powder. Another object of the invention is to provide improvedclassifying means for separating the material being treated in acommlnuting system, into several grades, and for delivering theseparated grades to apparatus which is especially adapted tosubsequently efiectively treat the several grades. A further object ofthe invention is to provide improved screening mechanism operabledirectly by the movement of a comminuting mill, and means associatedwith the screen for distributing the screened material. Still anotherobject of the invention is to provide an improved attachment tor rotarycomminuting mills wherein the material is reduced by stages,

which will insure delivery of material of proper mesh to each of theseveral comminuting chambers for effecting the several stages ofreduction. A further object of the invention is to provide an improvedmultiple compartment comminuting mill wherein freely tumbling.comminuting bodies are utilized, and in which the action or these bodiesis not interfered with by screens or the like. These and other objectsand advantages of the invention will be apparent in the course of thefollowing description.

A clear conception of an embodiment of the invention and of the mode ofoperating devices constructed in accordance therewith,

may be had by referring to the drawing ac-.

companying and forming a part of this specification in which the variousparts have been referred to by suitable reference characters.

The single figure ot the drawing is a relativelydiagrammaticillustration of a multiple compartment tube mill having the improvedclassifying or screenmg device associ-,

ated therewith.

In the drawing, the multiple compartment comminutin mill comprises ingeneral an elongated shel or drum 5 supported for rotation about asubstantially horizontal axis, by means of feed and discharge endtrunnions 6, i", and having therein two partitions 39,

which divide the interior or thedrum into I successive comminut'mgchambers 2, 3, i hav- The coarse grinding chamber 2 one be formed oflarger diameter than the ot ers, and mayalso be provided with a taperedportion as shown, at the discharge end thereof The feed trunnion 6located at the inlet ,end of the chamber 2, is provided with a feeder 9cooperating with a tapered end liner 28, for introducing the untreatedmaterial to the mill. After being initially reduced in the chamber 2 bythe large comminuting bodies 29, the material is delivered th'roughanend screen 10 and through a series of peripheral ()pBIllIlgS 36, to oneend of an outer screen 11. The screen 11 is attached directly to and isrotatable with the drum 5, and has the end thereof remote from theopenings 36, open for the discharge of rejects which fail to passthrough the screening openings during rotation of the screen. Locateddirectl beneath the annular outer screen 11 is a stationary receptacle13 forming a trough one end of which is closed by a wall secured to thereceptacle and extending in close proximity to the peripheral edge ofthe screen. A spiral conveyer 12 which is attached directly'to thescreen 11 cooperates with the receptacle 13 to urge material deliveredthereto throu h the screen 11, along the receptacle in a irectlon awayfrom the wall 15. A stationary receptacle 14 disposed atr'the end of thescreen 11 ad3oining the wall 15, is adapted to receive the re]ects fromthe interior of the rotating screen 11. The drum 5 is provided withspiral scoops 18 at the medial portion of the coarse grinding chamber 2,and these scoops 18 are adapted to return the screen rejects enteringthe receptacle 14, to the interior of the chamber 2 for furtherreduction.

The material delivered from the rece ta cle 13 bythe conveyor 12, isdischarged into a stationary receptacle 16 from whence it isautomatically removed and injected into the feed end of the intermediatecomminutin compartment 8, by means of spiral scoops 1% secured to andoperable by the movement of the drum 5. In the intermediate cham ber 3to a bucket elevator 22 which raises the said material and delivers thesame to an air separator. The air separator consists of a housing withinwhich is located a distributing rotor 33 and a fan 32. The rotor 33 isdisposed directly above a hopper 34 which is adapted to collect theoversize and to deliver the same through a spout 37 to the stationaryreceptacle 16, from whence this oversize is delivered together with thematerial received from the receptacle 13, to the intermediatecomminuting compartment 3. The hohsing of the dust collector is providedwith a conical bottom forming a collecting hopper for thefine-materialremoved by the air separator. fine material deposited thereon, through aspout 38 to a stationary receptacle 23 located below the inlet end ofthe fine. rinding compartment 4. The operation 0% the air separator iswell known to those skilled in. the art, the material delivered to therotor 33 bein thrown outwardly toward an interior ba e by centrifugalforce, and the air current induced within this baflie by the fan 32picking up the lighter particles, which, after passing t rough the fan,are thrown outwardly against the housing wall and eventually drop bygravity upon the conical bot tom 35 from which they are discharged byavity. i

The feed end of the fine grinding compartment or chamber 4- is providedwith petill ripheral scoops 24 which remove the relatively fine materialfromthe stationary receptacle 23 and introduce the same into the chamber4r. The tumbling coinminuting bodies 31 within the chamber at reduce thegraded material thus admitted, to a fine powder. The finally reducedmaterial is eventually discharged through an internal grating 25, intothe ath of elevating vanes 26 which lift the final product and dischargethe same through an opening 2'? in the trunnion 7, in an obvious manner.Continuous rotation may be imparted to. the drum 5, the scoops 17,

18, 24, and to the screen 11, by means oi! a driving gear 8 located atthe discharge end of the mill. 1 r V From the foregoing description itwill be noted thatduring normal operation of the mill, the revolvingscreen 11 serves toss arate the oversize from the relatively inc Theconical bottom 35 delivers- .ters Patent rectly to the screen 11 minimumhead room is required in order to deliver the fine material from thereceptacle 13 into the receptacle 16. The screen 11 may obviously bemade of any desired length in order to insure efiective removal of thefines, and the spiral return scoops 18 serve to deliver the rejects tothe medial portion of the comminutin chamber 2 so that they may beeffectively reduced during subsequent travel through this chamber. Theclassifying devices besides being highly efi'ective in operation, isalso extremely compact and accessible and does not in any mannerinterfere with the free tumbling action of the comminuting bodies withinthe mill.

It is to be noted that the novel use of an air separator for the purposeof classifying preliminarilyreduced material in order to separate thefines from the coarse material, and the [further reduction of theseparated fine material alone in a comminuting chamber, while beingdisclosed in connection with the present invention, forms no partthereof, and is the subject of a copending application Serial No.256,209, filed February 23, 1928. The present invention is howeverespecially adapted for use in connection with thisprior invention, inorder to insure the production of extremely fine pulverulent materialsuch as is required in the manufacture of cement.

It should be understood that it is not desired to limit the presentinvention to the exact details of construction and operation hereinshown and described for various modifications within the scope of theclaims may occur to persons skilled in the art.

lit is claimed and desired to secure by Let- 1. In combination, a rotarydrum forming a connninuting chamber, a'scrcen'communieating with saidchamber and rotatable with said drum, a stationary receptacle disposedbeneath said screen, a second stationary receptacle communicating withthe interior of said screen, a conveyer secured to said screen andmovable in said first mentioned receptacle to urge material deliveredthereto through. said screen along said receptacle ill) longitudinallyof the axis of said drum, and

means for returning to said drum material delivered from said screen tosaid second receptacle.

2. In combination, a rotary drum forming a comminuting chamber, a screencommunieating with said chamber and rotatable with said drum, areceptacle independent of said drum disposed beneath said screen, asecond receptacle independent of said drum communicating with theinterior of said screen, a conveyor operable by the rotation of saiddrum to urge material delivered to said first mentioned receptaclethrough said screen toward an end of said receptacle, and means forreturning to said drum material delivered from said screen to saidsecond receptacle.

3. In combination, a rotary drum forming a comminuting chamber, a screensurrounding and communicating with said chamber, said screen beingrotatable with said drum, a receptacle independent of said drum disposedbeneath said screen, a second receptacle independent of said drumcommunicating with the interior of said screen, a conveyer secured tosaid screen and movable thereby within said first mentioned receptaclet9 urge material delivered through said screen toward an end thereof,and means rotatable with said drum for returning thereto materialdelivered from said screen to said second receptacle.

4. In combination, a rotary drum forming acom'minuting chamber, a screensurroundingand communicating with said chamber, said screen beingrotatable with said drum, a stationary receptacle disposed beneath saidscreen and formed to receive material passing therethrough, a secondstationary receptacle for receiving from said screen material whichfails to pass therethrough, means for returning material which fails topass through said screen to said chamber, and means operable by themovement of said screen for urging material delivered to said firstmentioned receptacle therealong longitudinally of the axis of rotationof said drum;

5. In combination, a rotary drum forming a plurality of comminutingchambers, a screen disposed concentrically of said drum andcommunicating with one of said chambers, said screen being rotata lewith said drum, a sta ionary receptacle disposed beneath said screen andformed to receive material passing thercthrough, a second Staeatin withsaid chamber, saidscreen surrounding said drum and being attacheddirectly t ereto so as to rotate therewith, a stationary receptacledisposed beneath saidscreen, a second stationary receptacle forreceiving rejects from said screen, a spiral conveyer secured directlyto the peri hery of said screen and cooperable with sai first mentionedreceptacle to urge screened material therealong, and a scoop carried bysaid drum for returning rejects from said second receptacle to saidchamber.

7. In combination, a rotary drum forming a comminuting chamber, a screensurrounding said drum and extending therealong, said screen beingattached directly to said drum and being spaced from the exteriorthereof, a stationary receptacle disposed beneath said screen andforming a trough spaced from the external screen' surface, a secondstationary receptacle for receiving rejects from the interior of saidscreen, a spiral conveyer secured directly to said external screensurface and cooperable with said trough to urge material passing throughsaid screen along said trough longitudinally of the axis of said drum,and a scoop carried by said drum for returning rejects from said secondreceptacle to said chamber.

8. In combination, a rotary drum forming a plurality of comminutingchambers, a screen surrounding said drum and communicating with an endof one of said chambers, said screen being attached directly to saiddrum and extending therealong, a stationary receptacle for receivingrejects from the interior of said screen, means associated with saiddrum beyond the end of said screen which communicates with said chamberfor returning rejects to said chamber, a second stationary receptacledisposed externally of said screen, a spiral conveyer secured directlyto said screen for urging material delivered to said second receptaclelongitudinally of said screen and away from said rejects returningmeans, and means for returning said last mentioned material to anotherof said chambers beyond the end of said screen.

In testimony whereof, the signature of the inventor is affixed hereto.

'RAY o. NEWHOUSE.

